The Research Of Precancerous Gastric Lesions, Gastric Cancer And Esophageal Cancer Based On The Metabolomics Technology

Objective:Our Subject used the latest systems biology technology-metabonomics to reveal the mechanism of tumorigenesis and discovered putative metabolic markers associated with gastric cancer (GC), analyzed the difference of of small molecules in plasma between esophageal cancer (EC) patients and healthy volunteers, cancer tissue and adjacent tissues. On the other hand, we also investigated the effects of drugs on the metabolic phenotype of esophageal cancer cells, which provided experimental evidences for related drugs used in clinical therapy of esophageal cancer.Methods:1Gas chromatography time-of-flight mass spectrometry (GC/TOF-MS) was applied to determine metabolites levels in plasma obtained from patients including chronic superficial gastritis(CSG), GC and precancerous changes. Principal component analysis (PCA) and statistics were employed to differentiate the stages and to identify the markers of gastric cancer.2We profiled the metabolites in tissues and plasma collected from patients with gastric cancer, postoperative GC patients (PGC), and control patients with chronic superficial gastritis (CSG). The metabolites in tissue and plasma characterizing GC from CSG and PGC were statistically identified; and the potential markers characterizing tumor microenvironment and the systemic environment were analyzed and correlated.3We analysised the metabolites in plasma collected from patients with esophageal cancer and healthy volunteers, and the metabolites in esophageal cancer tissues and adjacent tissues. Furthermore, we used flow cytometry and MTT methods to study the effect of2-deoxyglucose (2-DG) on cell cycle, apoptosis and proliferation of esophageal cancer cell Eca109. Results:1CSG showed distinct difference from the other groups of chronic atrophic gastritis (CAG), ntestinal metaplasia (IM), gastric dysplasia (DYS)and GC, whose plots clustered closely. Twelve identified metabolites contributed most to the differentiating between CSG and GC, and characterized different stages of GC. And GC patients were obviously involved in oxidative stress, and perturbed metabolism of amino acids and fatty acids.2The tissues and plasma of the GC patients showed distinctly different metabolic phenotypes from those of the CSG controls. Significantly elevated glycolysis, tricarboxylic acid cycle (TCA), and amino acids turnover characterized metabolism of GC tissues; and greater metabolic perturbation were observed in GC tissues than that in GC plasma, both compared with the controls. Remarkably, the levels of the metabolic markers characterizing GC were not positively correlated in tissues and plasmas. For examples, TCA intermediates, lactate, amino acids and free fatty acids were more abundant in the tissues but less concentrated in plasma relative to their CSG controls; while glucose was lower in both the tissues and plasma of GC patients than the controls. The surgical removal of the GC tissue restored the levels of the molecules cited above to different extent in postoperative GC patients。3Levels of glucose, most free fatty acids and amino acid in the plasma collected from patients with esophageal cancer were significantly lower than that in the control sample, while levels of intermediates of the TCA and lactate were higher than the control. In esophageal cancer tissue, levels of most free fatty acids, amino acids, the TCA intermediates are higher than that in the adjacent tissues, while levels of glucose and lactic acid in cancer tissues were lower than the adjacent tissues. when treated under lower levels of02and increased concentrations of drugs, the inhibition rate of2-DG on Eca109cell growth increased gradually, and G1phase arrest and apoptosis became more eviden Conclusion:1The metabolic phenotype of CSG is significantly different from, while that of IM is similar to GC. The discriminatory metabolites characterizing progressive stages from CSG to GC might be the potential markers to indicate a risk of GC. Obvious metabolic perturbation of glycolysis, TCA and amino acids turn over were indicated based on the levels of metabolites in tissues and plasma from GC patents. Remarkably, the levels of the metabolic markers characterizing GC were not positively correlated in tissues and plasmas, indicating the complex relationship of systemic environment to tumor microenvironment. The results further suggested that metabolomic analysis of intact tissues is potentially an alternative technique for the clinical diagnosis of GC, and the analysis of plasma in post GC patients is a potential approach to assessing the effectiveness of a surgery.2The enhanced glycolysis and dysfunction of TCA cycle in tumor microenvironment. Levels of most amino acids, free fatty acids in the esophageal cancer tissues were higher than that in the adjacent tissues, while they were lower in esophageal cancer plasma than that in the control group. These regular changed metabolites were potential biomarkers of esophageal cancer3Glycolytic inhibitors can significantly inhibit the growth of Eca109cells, induce G1phase arrest and apoptosis, change cell metabolism and levels of metabolites, and these are significantly correlated with drug dose and oxygen concentration. It is suggested that2-DG showed anti-tumor cytotoxic effect. We concluded that metabolomic technique based on GC/TOFMS can be used for the evaluation of the anticancer drug efficacy and exploration of mechanisms of drug metabolism.